The present invention relates to gas generators in general, and more specifically, relates to inflators in vehicle occupant protection systems. Gas generators typically include a primary gas generant to produce sufficient amounts of gas to inflate an associated airbag and/or actuate an associated seatbelt pretensioner, for example.
As an enhanced safety feature, gas generators may be provided with an auto-ignition composition that automatically ignites at a relatively low temperature should a fire occur. In this way, the primary gas generant is safely managed to combust in a normal manner, notwithstanding the occurrence of the fire.
A booster composition may also be employed, whereby ignition of the booster composition rapidly increases the internal pressure of the inflator thereby ensuring an adequate combustion pressure for optimal combustion of the primary gas generant.
One concern that may be present with the use of the auto-ignition composition, and perhaps with the use of chemical compositions in general, is the potential for certain constituents in the compositions to age over extended periods of time in widely differing global climates, for example. Off-gassing, or the release of gases liberated by heat over time from various compositions within the gas generator, could occur and result in variability in the performance of the gas generator. To ensure consistency of performance of the inflator in the presence of “off-gases”, or to reduce potential variability of the associated functions of the respective compositions within the gas generator, it would be an improvement in the art to mitigate the effect of any potential off-gas products.
Accordingly, ongoing efforts in the design of automotive gas generating systems, for example, include initiatives that would manage any potential performance variability due to off-gassing over time.